I must say I really enjoy working with your project, and I have managed to get it to do everything I need.

However, I have a problem I am trying to work around. I am in need of only having pins that are in a placemark group cluster.

It seems I can only have all pins on a map cluster into groups or none of them. What I need to have happen is assign certain pins to a group and then have ONLY those pins appear as a cluster so when the user clicks on the cluster the pins will spiral out from there to display all of the pins in the cluster.

Hi
You can't control which placemarks will be clustered and which - no.
All placemarks processed by clusterer, and there is only one difference
- if "Group placemarks in cluster by placemark group property" set to No - all placemarks processed by one default clusterer
- if you set to Yes - for each group will be created separate clusterer, and each group will be clustered separately. In this case you can also override cluster icon